The present invention relates to a junction between car bodies of a track-bound vehicle, especially of a magnetic levitation train, having doors within adjacent end walls of the car bodies which doors are guided within the car bodies and serve to close the doorways within the end walls.
With magnetic elevation trains extremely high velocities can be achieved. This leads, when passing through curves, to high centrifugal forces which require compensation. Such compensation is achieved with a suitably designed track, i.e., with respectively elevated curves. When a magnetic elevation train passes through such elevated curves at a velocity which is substantially below the predetermined velocity for such curves or when the train comes to a stop within such an area of the track, gravitational forces of a considerable magnitude act on the slanted train, especially on the doors closing the doorways at the end walls of the car bodies. Such doors are commonly fire protection doors of considerable weight. Accordingly, the drives for the activation of these doors must have great power. When such drives become inoperable, for example, due to a collision, a manual opening of the respective door against the gravitational forces present as a function of the tilt of the car body is very difficult or even impossible.
For reducing the forces needed to activate the doors it is known to guide the doors without play and to support the doors in a friction-reducing manner. However, with such measures only for relatively small tilts of the car body relative to the maximal possible tilt it is possible that the doors at the junction between the car bodies can be opened with relatively small forces, that is also by hand, against the effect of the gravitational forces.
It is furthermore known from German Offenlegungsschrift 36 02 781 to prestress vehicle sliding doors, especially intermediate doors of train car bodies, in the closing direction by a prestressed cable whereby the prestress is generated by a spring.
However, the prestress provided for automatically closing the intermediate doors cannot be adjusted in its effect to changing tilts of the car bodies so that on certain portions of the track the gravitational forces resulting from the tilt and the spring force for loading the cable must be overcome by a respectively high counter force in order to be able to open the doors.
It is therefore an object of the present invention to provide a junction of the aforementioned kind with which it is possible, even for a considerable tilt of the car bodies relative to the longitudinal axis of the train, to open the doors at the junction with a small force against the effect of the gravitational forces resulting from the tilt.